Filing tool



March 24, 1942. R. w. HAMILTN 2,277,639

FILINGTooL Filed oct. 16. 1940 lfull surface bearing between thecontacts.

Patented Mar. 24, 1942 UNITED STATES PATENT OFFICE FILDNG TOOL Robert W.Hamilton, Philadelphia, Pa.

Application October 16, 1940, Serial No. 361,414

f 12 Claims.

This invention relates to filing tools, and more to redress the faces ofthe contacts and, for the most efficient operation of the same, it isdesirable that the faces be trued up so that when the contacts abutagainst each other, there will be a It will, therefore, be understoodthat the redressing of the faces of the contacts is difficult of properaccomplishment.

For the foregoing purpose there are procurable thin flat files which areadapted tov be inserted between the faces of the contacts but, by reasonof the faces of such files being parallel, there is no allowance for theslight relative angularity of the faces which occurs when the contactsare separated for the insertion of the file therebetween. Some mechanics,prefer to remove' the l s Thev principal object of the presentinvention is to provide a tool by means of which the contacts of thedistributors ofv automotive engines and the like may be conveniently andaccurately dressed without removing or dismantling the disy tributors orany of the parts thereof.

A further object of the invention is to provide a tool of the characteraforesaid by means of which the faces of the contacts may be dressed insuch relationship that, when the'contacts are brought together, thefaces thereof will engage each other throughout.

A further object ofthe invention is to provide a Ytool of the characteraforesaid in which the filing unit may be axially turned with respect tothe operating members whereby the tool may be used in various positionsand may also be used for the dressing of contacts which might otherwisebe inaccessible.

A further object of the invention is toA provide, in a tool of thecharacter aforesaid, means for compensating for differences inangularity of the faces of the separated contacts which occur by reasonof differences in the lengths of the pivoted contact arms.

A further object of the invention is to provide a tool of the characteraforesaid in which the ordinary thin flat les may be employed andutilized until the same are completely worn out throughout the greaterpart of their length.

The nature and characteristic features of the invention will be morereadily understood from the following description taken in connectionwith the accompanying drawing forming part .hereof in which:

Figure 1 is a side elevation of a ling tool embodying the main featuresof the present invention;

Fig. 2 is a front elevation thereof;

Fig. 3 is a horizontal section, enlarged, taken approximately on theline 3-3 of Fig. 1;

Fig. 4 is a similar view'taken approximately on the line 4-4 ofFig. 1;

Fig. 5 is a horizontal section, enlarged, taken on the line 5 5 of Fig.l;

Fig. 6 is a transverse section, enlarged, of a modified form of fileadapted for use in the tool of the present invention; and

Fig. 7 is a top or plan view of a portion of a distributor headillustrating the application of the operating portion of the tool forthe dressing of the contacts thereof.

It will of course be understood that the descriptionanddrawing hereinlare illustrative merely, and that various changes and modifications maybe made in the structure disclosed without departing from the spirit ofthe invention.

Referring now more particularly to Figs. l to 5 of the drawing, in theparticular embodiment of the invention therein shown, IiI and II are theoperating handles of the tool, pivoted to each other by means of a boltI2, and normally impelled to their most widely separated positions bymeans of a coil spring i3 disposed between said handles I0 and l.

The handle member i0 is provided, beyond the pivot bolt I2, withforwardly extending side members I4, the front ends I5 of which arecurved to permit the positioning therebetween of a ring member I6. Thering member It is provided with an annular groove I'I for the mountingtherein of a two part collar I8. Each end of each half of the collar I8is bent outwardly as at I9 to provide trunnions 'which are journalled inapertures 20 in the curved portions I5 of the portions I4 of the handlemember I0.

The ring member I6 is provided with a downwardly extending strut orstandard 2i. The lower end of the strut 2l is provided with a recess asat 22'for the mounting therein of a foot member 23. The foot member 23comprises two side plates 24 spaced from each other at the properangularity by means of end blocks Ztand 26, andV secured to each otherby means of rivets 2l passing throughv said end blocks. Each of theplates 24 is provided. with an aperture 23 of sumcient size to permitthe contacts of the distributor to pass therethrough to engage theworking faces of the file unit in the manner to be presently described.

The ring member I6 is also provided with a downwardly depending fiatspring member 29, the lower end of which is reduced in width to passthrough the space between the plates 24 of the foot member 2.3. Thelower portion of the spring member 29 is bent around as at 3i) on theunder side of the block member 25 of the foot member 23. The foregoingarrangement is such that when the le unit is removed from the tool, thelower end of the spring 29 may be pressed toward the lower end of thestrut 2l to permit Ythe foot member 23 to be removed and replaced byanother of dierent size or shape. When, however, the le unit is inplace, the spring 29 will be locked against such movement and the footmember 23 will thereby be secured in proper position at the lower end oflthe strut 2| and of the spring 29.

The handle member I l is also provided, beyond the pivot l2, withforwardly extending side members 34, the front ends 35 of which arecurved to permit the positioning therebetween of a head member 35. Thehead member 35 is cylindrical externally and is provided with an annulargroove 31 for the mounting therein of a two part collar 38 similar tothe collar I8. Each end of each half of the collar 38 is likewise bentoutwardly as at 39 to provide trunnions which are journalled inapertures 40 in the curved portions 35 of the portions 34 of the handlemember Il.

'Ihe head member 35 is also provided with an aperture 4I extendingvertically therethrough, said aperture 4| being sector shaped inhorizontal plan, thereby to provide an abutting surface 42 against whichthe nle unit is adapted to be clamp-ed. The clamping means .preferablyincludes a plate member 43 which bears against the file unit and isadapted to clamp the same in the head member 35 upon the tightening of aset screw 44 which is also mounted in the head member 35. The upper endof the clamping plate 43 is bent over as at 45 at the top of the headmember 3S to assist in positioning the same when the file unit ismounted in the tool.

Each of the handle members H is provided with a lug 46 on each sidethereof which lugs, when the handle members are separated to their limitpositions, bear against portions of the handle member I and thus preventthe jaw portions of the handle members Il! and ll from being separatedto such an extent as would permit the lower end of the file unit frombeing Withv drawn from the foot member 23.

The file unit preferably comprises two of the ordinary thin iiat files41, such as may be readily found on the market and which are intended tobe used for the purpose of ling the contacts of electrical make andbreak devices. These iiles are ordinarily made of thin flat steel withparallel faces, the le teeth being provided over a considerable portionof the length, and the other part of the length being left uncut andusually shaped in the form of a handle.

A spacer strip 48 is also provided, said spacer strip 48 beinginterposed between the two thin le members 41. The faces of the spacerstrip 48 are disposed at a slight angle with respect to each other sothat the les will be clamped in the tool with their outer faces at thedesired angularity. A plurality of said spacer strips 48 are preferablyprovided, each of a different angularity, whereby the tool .may bereadily adapted for use in dressing the contacts of differentdistributors, it being understood that the contact arms of suchdistributorsare not of standard length and hence the angularity of thefaces of the contacts for a given separation will vary in the differentmodels.

However, if desired a single le 49 having the faces thereof at theproper angularity, as shown in cross section in Fig. 6 of the drawing,may be employed in lieu of the two thin flat iiles 41 and the spacerstrip 48 as shown in the other gures of the drawing.

The operation of the tool may now be explained, reference being had moreparticularly to the arrangement as shown in Figs. 1 to 5 of the drawing,in which a pair of thin at files 41 are used with an interposed spacer48 of the proper angularity. The le unit, as above, is mounted in thetool with the end of said le unit positioned within the foot member 23.The contact arm 50 of the distributor (see Fig. '1) is now manuallyretracted and the foot portion 23 of the tool inserted between thecontacts 5| and 52 in such position that said contacts may extendinto-the apertures of the foot member and bear against the working facesof the file unit at this point.

Preferably, in order to get prop-erpressure to effect a rapid andefiicient cutting to dress the faces of the contacts, the end of thecontact arm 5i) and Ithe stationary contact support 53 are engaged bythe jaws of a pair of ordinary pliers (not shown) which will cause thesame to bear against the cutting faces of theiile unit with therequisite amount of pressure.

The handle members I0 and Il are now periodically squeezed toward eachother to cause the end of the file unit, which is positioned within thefoot member 23, to be reciprocated up and down and thus effect the lingof the faces of the contacts for Athe purpose of kdressing the same.

. After the action has proceeded fora suicient time, the pressureon thecontactarm 5B and the stationary support `53 Vis released, the contactarm 55 being then retracted a suiiicient distance to free the contacts5i and `52 from the footv member, after which the tool may be removed.

It will be found that ordinarily the surfaces of the files .which haveengaged the contacts will be worn away in one or two dressingoperations, this by reason of -the extreme hardness of the contacts usedin the distributors. In order to present a fresh cutting surface, thepressure of the clampingplate 43 provided by the set screw 44 may berelieved, and the files 41 and spacing member 4B removed. The les 41 maythen be turned around to present the other faces. The le unit is thenreinserted in the tool and clamped in place therein as hereinbefore setforth.

After the end portions of each of the les 41 has been worn on both facesso that the end portions Vof the files are no longer serviceable, theles 41 may then have small portions at the ends thereof broken oif whichwill permit new and fresh portions of the les 41 to be brought to theoperative location within the foot member 23.

I claim:

1. A portable hand tool for dressing the contacts Aof electrical makeand break devices comprising a le unit, two members movable toward vandaway Vfrom each other, parts connected to said members for manualactuation thereof, means carried by one of said members for clamping theiile unit thereto, parts carried by the other member and extendingtherefrom, and a foot member .supported .by said extending parts and inwhich the end of the file unit is guided.

2. A portable hand tool for dressing the contacts of electrical make andbreak devices comprising a file unit, two members movable toward andaway from each other, parts connected to said members for manualactuation thereof, means carried by one of said members for clamping theflle unit thereto, parts carried by the other member and extendingtherefrom, and a foot member supported by said extending parts and inwhich the end of the i'lle unit is guided, said foot member having apair of spaced side plates between which the end of the file unit isreciprocated.

3. A tool for dressing the contacts of electrical make and break devicescomprising a iile unit, two members movable toward and away from eachother, means carried by one of said members for clamping the le unitthereto, parts carried by the other member and extending therefrom, anda foot member supported by said extending parts and in which the end ofthe le unit is guided, said foot member having a pair of angularlyspaced side plates apertured to permit the contacts to engage theworking faces of the file unit as the same is reciprocated in the footmember.

4. A portable hand tool for dressing the contacts of electrical make andbreak devices comprising a file unit, two members movable toward andaway from each other, parts connected t said members for manualactuation thereof, means carried by one of said members for clamping thele unit thereto, parts carried by the other member and extendingtherefrom, and a foot member removably supported by said extending partsand in which the end of the file unit is guided.

5. A tool for dressing the contacts of electrical make and break devicescomprising a file unit, a pair of pivoted handle members havingextending jaw portions, a head member mounted in the jaw portion of oneof said handle members, parts mounted therein for clamping the file unitthereto, another member mounted in the jaw portion of the other handlemember, parts carried by and extending from said member, and a footmember supported by said extending parts and in which the end of the leunit is guided.

6. A tool for dressing the contacts of electrical make and break devicescomprising a file unit, a pair of pivoted handle members havingextending jaw portions, a head member mounted in the jaw portion of oneof said handle members, parts mounted therein for clamping the le unitthereto, another member mounted in the jaw portion of the otherhandle-member, parts carried by and extending from said member, and afoot member supported by said extending parts and in which the end ofthe file unit is guided, said foot member engaging portions of thecontacts to maintain the Working faces of the file unit in properrelationship with said contacts.

7. A tool for dressing the contacts of electrical make and break devicescomprising a le unit, a pair of pivoted handle members having extendingjaw portions, a head member rotatably mounted in the jaw portion of oneof said handle members, parts mounted therein for clamping the file unitthereto, another member rotatably mounted in the jaw portion of theother handle member, parts carried by and extending from said member,and a foot member supported by said extending parts and in which the endof the file unit is guided.

8. A tool for dressing the contacts of electrical make and break devicescomprising a file unit, a pair of pivoted handle members havingextending jaw portions, a head member rotatably mounted in the jawportion of one of said handle members, parts mounted therein forclamping the file unit thereto, another member rotatably mounted in thejaw portion of the other handle member, parts carried by and extendingfrom said member, and a foot member supported by said extending partsand in which the end of the le unit is guided, said foot member engagingportions of the contacts to maintain the Working faces of the file unitin proper relationship with said contacts. l

9. A tool for dressing the contacts of electrical make and break devicescomprising a file unit, a pair of pivoted handle members havingextending jaw portions, a head member mounted in the jaw member of oneof said handle members, parts mounted therein for clamping the file unitthereto, another member mounted in the jaw portion of the other handlemember, parts carried by and extending from said member, and

a foot member removably supported by said ex-V tending parts and inwhich the end of the file unit is guided.

l0. A tool for dressing the contacts of electrical make and breakdevices comprising a file unit, two members movable toward and away fromeach other, means carried by one of said members for clamping the leunit thereto, parts carried by the other member and extending therefrom,a foot member supported by said extending parts and in which the end ofthe illev unit is guided, said foot member having portions engagingportions of the contacts thereby to position the Working faces of the leunit with respect to said contacts, said foot member being removablefrom its supports for replacement by another of different size or shape.

ll. A tool for dressing the contacts of electrical make and breakdevices comprising a file unit, two members movable toward and away fromeach other, means carried by one of said members for clamping the fileunit thereto, parts carried bythe other member and extending therefrom,a foot member supported by said extending parts and in which the end ofthe file unit is guided, said foot member having a pair of spaced sideplates apertured to permit the contacts to engage the working faces ofthe file unit as the same is reciprocated in the foot member, and saidfoot member being removable from its supports for replacement by anotherof different size or shape.

12. A tool for dressing the contacts of electrical make and breakdevices comprising a file unit, two members movable toward and away fromeach other, means carried by one of said members for clamping the fileunit thereto, parts carried by the other member and extending therefrom,a foot member supported by said extending parts and in which the end ofthe le unit is guided, said foot member having a pair of angularlyspaced side plates apertured to permit the contacts to engage theWorking faces of the file unit as the same is reciprocated in the footmember, one of the parts for supporting the foot member being movablewith respect to the other when the file unit is removed from the footmember thereby to release said foot member for replacement by another ofdifferent size or shape.

ROBERT W. HAMILTON.

